/*  $NetBSD: setjmp.h,v 1.5 2013/01/11 13:56:32 matt Exp $  */
/* $FreeBSD$ */

/*
 * machine/setjmp.h: machine dependent setjmp-related information.
 */

#ifndef _MACHINE_SETJMP_H_
#define _MACHINE_SETJMP_H_

#define _JBLEN  64      /* size, in longs, of a jmp_buf */

/*
 * NOTE: The internal structure of a jmp_buf is *PRIVATE*
 *       This information is provided as there is software
 *       that fiddles with this with obtain the stack pointer
 *   (yes really ! and its commercial !).
 *
 * Description of the setjmp buffer
 *
 * word  0  magic number    (dependent on creator)
 *  13  fpscr       vfp status control register
 *  14  r4      register 4
 *  15  r5      register 5
 *  16  r6      register 6
 *  17  r7      register 7
 *  18  r8      register 8
 *  19  r9      register 9
 *  20  r10     register 10 (sl)
 *  21  r11     register 11 (fp)
 *  22  r12     register 12 (ip)
 *  23  r13     register 13 (sp)
 *  24  r14     register 14 (lr)
 *  25  signal mask (dependent on magic)
 *  26  (con't)
 *  27  (con't)
 *  28  (con't)
 *  32-33   d8      (vfp register d8)
 *  34-35   d9      (vfp register d9)
 *  36-37   d10     (vfp register d10)
 *  38-39   d11     (vfp register d11)
 *  40-41   d12     (vfp register d12)
 *  42-43   d13     (vfp register d13)
 *  44-45   d14     (vfp register d14)
 *  46-47   d15     (vfp register d15)
 *
 * The magic number number identifies the jmp_buf and
 * how the buffer was created as well as providing
 * a sanity check
 *
 * A side note I should mention - Please do not tamper
 * with the floating point fields. While they are
 * always saved and restored at the moment this cannot
 * be garenteed especially if the compiler happens
 * to be generating soft-float code so no fp
 * registers will be used.
 *
 * Whilst this can be seen an encouraging people to
 * use the setjmp buffer in this way I think that it
 * is for the best then if changes occur compiles will
 * break rather than just having new builds falling over
 * mysteriously.
 */

#define _JB_MAGIC__SETJMP   0x4278f500
#define _JB_MAGIC_SETJMP    0x4278f501
#define _JB_MAGIC__SETJMP_VFP   0x4278f502
#define _JB_MAGIC_SETJMP_VFP    0x4278f503

/* Valid for all jmp_buf's */

#define _JB_MAGIC        0
#define _JB_REG_FPSCR       13
#define _JB_REG_R4      14
#define _JB_REG_R5      15
#define _JB_REG_R6      16
#define _JB_REG_R7      17
#define _JB_REG_R8      18
#define _JB_REG_R9      19
#define _JB_REG_R10     20
#define _JB_REG_R11     21
#define _JB_REG_R12     22
#define _JB_REG_R13     23
#define _JB_REG_R14     24

/* Only valid with the _JB_MAGIC_SETJMP magic */

#define _JB_SIGMASK     25

#define _JB_REG_D8      32
#define _JB_REG_D9      34
#define _JB_REG_D10     36
#define _JB_REG_D11     38
#define _JB_REG_D12     40
#define _JB_REG_D13     42
#define _JB_REG_D14     44
#define _JB_REG_D15     46

#ifndef __ASSEMBLER__
#if __BSD_VISIBLE || __POSIX_VISIBLE || __XSI_VISIBLE
typedef struct _sigjmp_buf { int _sjb[_JBLEN + 1]; } sigjmp_buf[1];
#endif

typedef struct _jmp_buf { int _jb[_JBLEN + 1]; } jmp_buf[1];
#endif

#endif /* !_MACHINE_SETJMP_H_ */
